It is, of course, known to react materials having primary amine groups, with compounds having carboxylic acid groups to produce polyamides.
U.S. Pat. No. 2,359,867 teaches polymers having a high receptivity for acid dyes, which polymers are the reaction product of 75 to 95 parts by weight of a mixture of hexamethylene diamine and adipic acid in substantially equal proportions, and 5 to 25 parts by weight of a polyamide-forming composition selected from the class of (a) mixtures of diamine and dibasic carboxylic acid in substantially equimolecular proportions, and (b) monoaminomonocarboxylic acids. The polyamide-forming composition has a bifunctional polyamide-forming reactant containing at least one oxygen atom in the chain of atoms separating its amide-forming groups. Such polyamide forming reaction may include compounds of the formula NH.sub.2 --(CH.sub.2 CH.sub.2 O).sub.x --CH.sub.2 CH.sub.2 --NH.sub.2, where x is from 2 to 3. Also of interest is S. Iwabuchi, et al., "Darstellung und Eigenschaften von Copolyamiden mit Oxyethylenegruppen in definierter Sequenz,"Makromol. Chem., Vol. 183, (1982) pp. 1427-1433. The summary to the article indicates that polyamides of the formula: ##STR1## were synthesized from .alpha., .omega.-diamino-substituted oligo(oxyethylene)s and bis-chlorides of dicarboxylic acids. The copolymers contained up to five oxyethylene units per repeating unit, and properties like solubility, thermal stability and complexing ability towards alkali metal cations were influenced.
See also Chemical Abstracts, Vol. 31:769 9 (1946) reporting Great Britain Patent 562,370 which describes a mixture of at least two preformed synthetic linear polyamides heated in the molten state at amide-forming temperatures until a homogeneous melt blend was obtained. At least one of the polyamides should be soluble in water and the other insoluble. The insoluble polyamide may be polyhexamethylene adipamide. The soluble polyamide may be one in which heteroatoms of oxygen or sulfur are present in the main polyamide chain, such as polytriglycol adipamide and N-methylpolytriglycol adipamide. The resultant polyamides had increased water-absorption properties and other improved properties.
A good, general background article about some of these amide materials is J. R. Flesher, Jr., "Polyether Block Amide: High-Performance TPE," Modern Plastics, September, 1987, pp. 100-110, where the family of engineering-grade thermoplastic elastomers based on block copolymers of polyethers and polyamides is discussed.
Also of interest is U.S. Pat. No. 5,086,162 to George P. Speranza and Wei-Yang Su of Texaco Chemical Company which describes novel polyether amides produced by reacting at least one polyalkylene glycol diamine with at least two dicarboxylic acids or esters thereof. The polyethylene glycol diamine has the formula NH.sub.2 --(CH.sub.2 CH.sub.2 O).sub.x --CH.sub.2 CH.sub.2 --NH.sub.2, where x ranges from 2 to 6, and at least one of the dicarboxylic acids is an aromatic dicarboxylic acid. These novel polyether amides may have the formula: ##STR2## where each R and R' are independently an alkyl or aryl moiety having from 3 to 34 carbon atoms, where at least one R or R' is an aryl moiety, and where each x and y independently have the values noted. Suitable dicarboxylic acids include adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, t-butyl isophthalic acid, and mixtures thereof. Suitable diamines include triethylene glycol diamine (JEFFAMINE.RTM. EDR-148 amine) and tetraethylene glycol diamine (JEFFAMINE.RTM. EDR-192 amine), among others. The resulting polyether amides are useful to make polymers, including fibers, with unusually good water absorbancy properties. The methods of this patent successfully incorporate triethylene glycol diamine and aromatic dibasic acids, where this cannot be accomplished directly.
Past research related to that described above has shown that it is not possible to incorporate higher molecular weight poly(propylene glycol) diamines into polyamide-6,6 segmented block copolymers; where higher molecular weight is defined as greater than 400 gm/mol. This is true despite the fact that poly(ethylene glycol) diamines have been readily incorporated, as described above. Poly(propylene glycol) diamines such as JEFFAMINE.RTM. D2000 diamine (Mw.apprxeq.2000) are not soluble in the monomers that are building blocks for polyamide-6,6 (hexamethylene diamine/adipic acid). The diamines tend to phase separate from the hexamethylene diamine/adipic acid in the polymerization reactor. The diamines thus cannot be efficiently incorporated into polyamide-6,6 to produce a polyetheramide-6,6 segmented block copolymer. There exists a need for way to incorporate these diamines into these polyamides.